Myocardial infarction (MI), commonly known as a heart attack, is the leading cause of death in United States. MI occurs due to the occlusion of the coronary arteries. This results in insufficient blood and oxygen supply that lead to damaged cardiac muscle cells and trigger a disease-induced degradation process. The accurate diagnosis of MIs is critical for timely medical intervention and maintaining quality of life.
An electrocardiogram (ECG) contains dynamic information pertinent to space-time cardiac electrical activity. The ECG signal is a temporal recording of cardiac electrical signal that initiates at the sinoatrial (SA) node, is conducted in both atria, and is relayed through the atrioventricular (AV) node to further propagate through the bundle of His and Purkinje fibers to provide ventricular depolarization and repolarization. The ECG signal is typically plotted as a trace that is segmented into a P wave, a QRS complex, and a T wave. Each segment is closely associated with the specific physical activities of the heart chambers. For example, atrial depolarization (and systole) is represented by the P wave, ventricular depolarization (and systole) is represented by the QRS complex, and ventricular repolarization (and diastole) is represented by the T wave.
The time-domain ECG and its features (e.g., Q wave, QT interval, ST elevation or depression, T wave) are often used to identify cardiovascular conditions, such as MI. However, because the ECG trace is a time-domain projection of space-time cardiac electrical activity, the ECG trace diminishes important spatial information of cardiac pathological behaviors. Accordingly, critical medical decisions are made without having all of the relevant information as to the condition of the heart, especially in cases in which there is a lesion in initial stages of growth.
In view of the above discussion, it can be appreciated that it would be desirable to have a system and method for diagnosing cardiovascular conditions that fully account for both time- and space-domain information about cardiovascular function.